Gravitational-Inertial Classifier

These units combine gravitational, inertial, centrifugal and aerodynamic forces to classify materials at cut points ranging from 50 to 200 mesh (300 to 75 microns). The feed material and primary air enter the top of the classifier in a downward direction. The air makes 120° change in direction and exits through the vanes carrying fine particles with it. The coarse particles, too heavy to make the turn, fall to the bottom to be discharged by a valve.

Secondary air, injected below the vanes, passes through the curtain of falling particles. Those particles near cutpoint in size are diverted by the secondary air stream into an eddy current within the heart-shaped chamber. The fines, some captured as they enter the unit and others drawn from the eddy, are carried by the exiting air to a fabric filter or cyclone for final recovery.

A simple, manual adjustment to the secondary air damper permits a change in the size of the fines being separated. The fact that there are no moving parts within the material flow stream reduces to a minimum the requirement for maintenance. For abrasive materials, liners are used in some areas to provide long life of the equipment.